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Fluorescent in situ Hybridization on Mitotic Chromosomes of Mosquitoes
Published on: September 17, 2012
Cytoplasmic incompatibility in natural populations of a mosquito, Culex pipiens L
Abstract:
When two strains of Culex pipiens (s.l.) of different geographical origin are cross-mated, the cross is frequently sterile in one or both directions. Such incompatibility is said to be cytoplasmic because the crossability of a strain is determined by its maternal lineage. The incompatibility is caused in some way by infection with a rickettsia-like bacterial symbiote, as removal of the symbiote abolishes the incompatibility. In compatibility has not been observed in crosses of American strains of C. pipiens. On the other hand, most workers in other parts of the world who have crossed C. pipiens strains have noticed incompatibility, although there are no reports of incompatible egg rafts being collected in the field. We now report incompatibility in crosses of sympatric American strains of C. pipiens and the collection of incompatible egg rafts in the field.
Insights
Incompatibility in Culex pipiens (s.l.) crosses, previously linked to bacterial symbiontes, is now observed in sympatric American strains. Incompatible egg rafts were collected in the field, challenging prior geographical assumptions.
Area of Science:
- Entomology
- Microbiology
- Genetics
Background:
- Cytoplasmic incompatibility (CI) in Culex pipiens (s.l.) is maternally inherited and linked to rickettsia-like bacterial symbiontes.
- CI has been widely reported globally but not previously observed in crosses of American C. pipiens strains.
Purpose of the Study:
- To investigate cytoplasmic incompatibility in sympatric American strains of Culex pipiens (s.l.).
- To determine if incompatible egg rafts can be collected in the field.
Main Methods:
- Cross-mating of different geographical strains of Culex pipiens (s.l.).
- Observation and documentation of cross-mating outcomes, including sterility and egg raft viability.
- Field collection of egg rafts.
Main Results:
- Incompatibility was observed in crosses of sympatric American strains of Culex pipiens (s.l.).
- Incompatible egg rafts were collected in the field, providing direct evidence of CI in this context.
Conclusions:
- Cytoplasmic incompatibility in Culex pipiens (s.l.) occurs within American populations, not just between geographically distant strains.
- The findings expand the known geographical distribution and ecological context of CI in this mosquito species.
